IMMUNOLOGICAL AND SIDE-EFFECTS OF LOW SC RECOMBINANT INTERLEUKIN-2 DOSE IN ADDITION TO CONVENTIONAL TREATMENT IN RELAPSED BREAST AND COLORECTAL-CANCER PATIENTS

Thirteen relapsed cancer patients, four of them operated for colorecta l and the nine remaining for breast cancer, were cyclically given low subcutaneous (sc) recombinant interleukin-2 (rIL-2) doses in addition to chemo- or hormone therapy. Cycle intervals were 2 or 6 weeks in len gth, and the number of cycles ranged from one to 14 and from one to si x respectively. Tolerance assessed by clinical and laboratory data, eo sinophils, lymphocytes (total number), T subpopulations, B lymphocytes and NK cells were the evaluated parameters. One (7.6%) of the 13 stud ied patients interrupted the first low dose sc rIL-2 cycle due to a hy persensitive reaction. This case showed relapse from breast cancer, Du ring further cycles, three patients (25%), one operated on for colorec tal and two others for breast cancer of the 12 remaining cases who com pleted all rIL-2 cycles showed an increase in glutamic oxaloacetic tra nsaminase (GOT), glutamic pyruvic transaminase (GPT), gamma-gt, and cr eatininemia without any clinical symptoms. A slight influenza-like syn drome and 10-20 mmHg decrease in blood pressure sporadically occurred in all patients under rIL-2 therapy. In both cancer types, a significa nt (P < 0.05-P < 0.001) increase in lymphocytes, eosinophils, T4 and T 3 subpopulations but nor in TS subpopulations and NK cells occurred at the end of the rIL-2 cycles, In 11 of the 13 patients responsive to c onventional therapy, a highly significant increase (P < 0.001) in all parameters apart from B lymphocytes and T4/T8 ratio was observed, whil e in three cases which were no longer responsive and in another case w hich had never been responsive to conventional therapy, a slightly sig nificant increase in eosinophils only occurred (P < 0.05). Three color ectal cancer patients showed a partial response and the last a complet e response to conventional therapy, In these four patients, time to pr ogression during rIL-2 cycles ranged from 2.5-5 months and the duratio n of response ranged from 8-19 months. In seven of the eight breast ca ncer patients who completed all rIL-2 cycles, the response ranged from 3-51+ months and in the last case, which was not responsive to conven tional therapy, the disease progressed in spite of the addition of rIL -2, These data suggest that: a) rIL-2 is Likely to constitute a well-t olerated and suitable home therapy even when cyclically given for a pr olonged period; b) following rIL-2 administration, eosinophils and lym phocytes increase in addition to the T subpopulations.